Determining the Effectiveness of Decontamination with Ionized Hydrogen Peroxide

Introduction: Ionized Hydrogen Peroxide (iHP) is a new technology used for the decontamination of surfaces or laboratory areas. It utilizes a low concentration of hydrogen peroxide (H₂O₂) mixed with air and ionized through a cold plasma arc. This technology generates reactive oxygen species (ROS) as a means of decontamination. Objectives: The purpose of this study is to evaluate the diffusion effect of iHP and its decontamination capabilities using biological and enzyme indicators. Methods: A gas-tight fumigation room with a volume of 880 ft³ was used for the decontamination trials. During the decontamination process, empty animal cages were placed inside to create fumigant distribution restrictions. Spore and enzyme indicators were placed in eleven locations throughout the decontamination room. Generation of iHP was done with the use of TOMI’s SteraMist Environmental System and the SteraMist Solution, with 7.8% H₂O₂ at a dose of 0.5 ml per ft³. Results: For the decontamination of 1hr, 2hrs, 6hrs, and 12hrs, the biological indicators of B. atrophaeus in Stainless Steel (SS) Disk in Tyvek envelope have an inactivation rate of 94%, 97%, 100%, and 100%, respectively. For G. stearothermophilus in SS disk and Tyvek envelope, it has 82%, 68%, 100%, and 100%, respectively and, for G. stearothermophilus in SS strips it has an effective rate of 88%, 67%, 91%, and 100%, respectively. Conclusion: iHP inactivates spores, and the residual tAK activity indicates a gas-like fumigant diffusion due to the uniformity of the inactivation without the use of oscillating fans as the contact time is extended.